Banking heir Alan Wilzig is getting a divorce and selling his Tribeca townhouse to live upstate near his estranged wife, Karin, their two kids — and his private racetrack.

Alan — younger brother of Ivan Wilzig, who is famous for his decadent Hamptons parties — split with Karin in July, just as they were moving to live full time on a 275-acre spread in Columbia County, where Alan built the country’s biggest private racetrack for $7.5 million.

“Karin has been nothing but sweet and kind and loyal, and is a wonderful mother. She just tired of baby-sitting me, given that my enthusiasm for racing, entertaining and otherwise being a ‘handful’ would make anyone rather weary after 20-plus years,” Alan, 51, told me.

“There was no single event that broke us, but rather an accumulation of selfishness on my part.”

Alan’s divorce should be finalized soon, and he has a photogenic new girlfriend, Clemence Lapeyre, 23.